Ground penetrating radar (GPR) systems are capable of detecting buried metal and non-metal objects, such as rocks, boulders and roots that are present below the ground surface. In addition, GPR systems can detect discontinuities and gradients in the dielectric properties of the soil due, for example, to soil layering, air voids, heterogeneous soil composition and moisture content. Air voids include tunnels, caves and other extended man-made and natural structures that form a void.
Many GPR systems are clutter-limited. Often, detection of only one type of feature is desired. In these instances all other surface and buried features are considered to be clutter. If the feature to be detected exhibits change over time, the feature can be separated from clutter features through change detection processing. In some applications, observations of an underground region are desired at widely separated times. Components of such systems can be sensitive to temperature variation; therefore change detection processing applied to measurements widely separated in time can yield poor results.
Many GPR systems are designed for stationary operation; however, in some applications, measurements of a large underground region or track are required therefore operation from a moving platform is desirable. Application of change detection processing to data acquired from a mobile GPR system using different measurement passes is prohibited by the inability to transport the GPR antenna system over the underground region in a near-identical manner for each measurement pass.